Saw-mill head-block



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cfr.

(No Mdel.)4 l H. R. BARNHURST.

SAW MILL HEAD BLOCK. No. 281,750. Pawnted J'u1y24, 188s.

UNITED STATES PATENT OFFICE.

HENRY R. BARNHURST, OF ERIE, PENNSYLVANIA.

SAW-MILL HEAD-BLOCK.

SPECIFICATION forming part of Letters Patent No. 281,750, dated July 24,1883.

Application filed January 6, 1883. (No model.)

To au whom it may concern:

Be it known' that I, HENRY B. BAENHURsT, a citizen of the United States,residing at Erie, in the county of Erie and State of Pennsylvania, haveinvented certain new and useful Improvements in Saw-Mill Head-Blocks;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to saw-mill headblocks; and it consists in,providing a construction whereby friction-roller bearings for thesetting-shaft may be used in each of the blocks. This construction isespecially desirable where the knees are reacted by springs, as is verycommon; but of course, whatever may be the construction or mode ofoperating the shaft, it is desirable that the friction of the shaft inits bearings in the blocks be as light as possible. When blocks havebeen in use a while they will become more or less loosened on theframe-work of 4the carriage, and then as a log is rolled onto them theyget slightly out of line and bind on the shaft in the bearings, and byusing friction-rollers in the bearings the bad effect of binding will beovercome very much.

The invention is illustrated in the accompanying drawings as follows:

Figure lis a side elevation of one of the blocks and knees, and showsthe friction-rollers in place. Fig. 2 is a vertical transverse sectionon the line x x in Fig. l. Fig. 3 is a perspective view with parts ofthe block and knee brokenxaway so as to show internal construction.

Parts are indicated by letters of reference as follows: A is the block;C, the shaft; H, the pinion on the shaft which operates the knee. B is alarge -boss on the sides of the block which forms the chamber around theshaft for the friction-rollers to lie in. E are the friction-rollers.

G is a collar forming a cap over the end of the boss, and serves t0close the end of the friction-roller chamber, and g2 g2 are the screwsfor holding the said collar in place.

The construction is as follows: At the point where the shaft passesthrough the block a circular opening is made which is as much largerthan the shaft as is necessary to admit of rollers being placed thereinall around the shaft. The walls of the block at this point are madethicker by the boss B, so as to allow the use of rollers of considerablelength. The rollers E, being in place, are retained from moving out ofplace lengthwise bythe pinion H on one side and the collar G on theother side. The collar G may be attached to the shaft, as is the pinion,or to the face of the boss, as it is shown to be in the drawings.

I have shown a system of rollers on cach side of the block; but it isnot necessary that there should be.

I am aware that various kinds of journalbearings have been provided withsets of friction rollers substantially as in this instance, and I do notVtherefore desire to be understood as claiming the use offrictionrollers in a journal-bearing, but simply as claiming the meansherein shown for applying the said friction-rollers to the setting-shaftof a saw-mill head-block.

What I claim as new is as follows:

Ina saw-mill head-block, the combination of the boss B, forming anannular chamber in the wall of said block around the shaft C, therollers E, lling said chamber, and the collar G and pinion H, closingthe ends of said chamber, substantially as and for the purposes setforth.

In testimony whereof I affix my signature in presence of two witnesses.

HENRY R. BARNIIURST.

Witnesses:

JOHN K. HaLLocK, R. H. PORTER.

